Elastomeric materials are used in various applications for sealing. Such a seal can be a dynamic or static seal. Depending on the environment, an elastomer seal can experience a range of temperatures, pressures, and chemicals. Elastomer seals can be used in high vacuum to multi-atmosphere pressures and from slightly below room temperature to elevated temperatures, e.g., 150° C. Both inert and reactive gases and liquids have been exposed to elastomers. While there exists no ideal elastomer seal, elastomers show a range resistance to chemical attack, thermal degradation, leak rate, and extrusion. In the oil and gas industry, an elastomer should maintain its mechanical properties under “wet” rather than under “dry” conditions at a given temperature, pressure, and service time while being exposed to corrosive chemicals.
Even with the most recent technologies, there nonetheless remains a need for elastomers, or any other polymeric materials, that function well and maintain their mechanical properties at high temperatures under wet conditions. High temperature polymers that are chemically resistant under dry conditions alone are readily available. Such polymers include certain thermoplastic polyimides (TPI) and polybenzimidazoles (PBI). Chemically resistant polymers useful under wet conditions at low temperature are also readily available. Examples of these polymers include certain polyethylenes and polypropylenes. Under conditions of high temperature and corrosive fluids, fluoropolymers are often used, as they are generally considered to have the best thermal stability and chemical resistance. Examples of fluoropolymers include polytetrafluoroethylene, and certain other fluoroelastomers and perfluoroelastomers. Certain grades of fluoropolymers are claimed to have a maximum continuous service temperature of 327° C. However, even the best perfluoroelastomers can become soft at high temperature over time, losing their capability to seal gaps under high pressure. Also, fluoroelastomers or perfluoroelastomers tend to develop cracks when contacted with various downhole fluids at high temperature.
Despite extensive research directed to replacing elastomers or increasing their resistance to degradation under high pressures, high temperatures and chemically and mechanically unforgiving environments such as in downhole conditions, there remains a need for elastomers having improved chemical resistance, particularly at such high temperatures. It would be a further advantage if the improved chemical resistance could be obtained without significantly adversely affecting other desirable properties of the elastomers, for example mechanical properties such as elasticity, extrusion resistance, and integrated structural strength. Materials and methods for elastomers useful in devices such as packers, blow out preventer elements, O-rings, gaskets, and the like that retain good mechanical properties at high temperature and high pressure when in contact with corrosive fluids over continuous service times would be well received in the art.